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grahamc/fstab.rs Secret

Created November 28, 2018 15:48
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fstab.rs
use regex::Regex;
lazy_static! {
static ref COMMENT_REMOVAL_REGEXP: Regex = Regex::new(
r"^\s*#.*$"
).unwrap();
}
/// A valid, parsed fstab file
#[derive(Debug, PartialEq)]
pub struct FSTabFile<'a> {
/// All the entries which were validly parsed
pub entries: Vec<FSTabEntry<'a>>,
}
/// A filesystem line
#[derive(Debug, PartialEq)]
pub struct FSTabEntry<'a> {
/// This field describes the block special device or
/// filesystem to be mounted.
pub spec: &'a str,
/// This field describes the mount point (target) for the
/// filesystem.
pub file: &'a str,
/// This field describes the type of the filesystem.
pub fs_type: &'a str,
/// This field describes the mount options associated with the
/// filesystem, in a comma separated list.
pub options: &'a str,
/// This field is used by dump(8) to determine which filesystems
/// need to be dumped. Defaults to 0.
pub dump: i8,
/// This field is used by fsck(8) to determine the order in which
/// filesystem checks are done at boot time. Defaults to 0.
pub fsck_pass: i8,
}
/// Parse a single line of an fstab
///
/// According to `man fstab` each line is a series of space-separated
/// fields. Leading spaces are ignored. Lines starting with a `#` are
/// skipped.
///
/// According to the source code (libmount/src/tab_parse.c) invalid
/// lines are simply skipped.
///
/// Note: According to the documentation, an fstab's `file` field can
/// contain spaces and tabs if they are represented by \040 and \011.
/// This function doesn't decode these octal characters.
pub fn parse_fstab_line<'a>(fstab: &'a str) -> Option<FSTabEntry<'a>> {
if COMMENT_REMOVAL_REGEXP.is_match(fstab) {
return None
}
let mut parts = fstab.split_whitespace();
let result = Some(FSTabEntry {
spec: parts.next()?,
file: parts.next()?,
fs_type: parts.next()?,
// "options" is required by the manual, but it seems they can
// be ommitted based on the util-linux source
// see: libmount/src/tab_parse.c
options: parts.next().unwrap_or(""),
dump: parts.next().unwrap_or("0").parse::<i8>().unwrap_or(0),
fsck_pass: parts.next().unwrap_or("0").parse::<i8>().unwrap_or(0),
});
if parts.next() == None {
return result
} else {
return None
}
}
/// Pass in an iterator of ftab lines, ie: "my\nfile".lines()
/// and get back a parsed representation of the file.
///
/// See parse_fstab_line for more information about edge cases and
/// specific behavior of this implementation.
pub fn parse_fstab<'a, T: Iterator<Item = &'a str>>(fstab_lines: T) -> FSTabFile<'a> {
FSTabFile {
entries: fstab_lines
.map(|line| parse_fstab_line(line))
.filter_map(|x|x).collect::<Vec<FSTabEntry>>()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn parse_fstab_line_comment() {
assert_eq!(
parse_fstab_line("# This is a generated file. Do not edit!"),
None
);
assert_eq!(
parse_fstab_line(" # This is a generated file. Do not edit!"),
None
);
}
#[test]
fn parse_fstab_line_valid() {
assert_eq!(
parse_fstab_line("/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc / ext4 defaults 0 1"),
Some(FSTabEntry {
spec: "/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc",
file: "/",
fs_type: "ext4",
options: "defaults",
dump: 0,
fsck_pass: 1
})
);
}
#[test]
fn parse_fstab_line_valid_default_opts() {
assert_eq!(
parse_fstab_line("/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc / ext4 defaults"),
Some(FSTabEntry {
spec: "/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc",
file: "/",
fs_type: "ext4",
options: "defaults",
dump: 0,
fsck_pass: 0,
})
);
}
#[test]
fn parse_fstab_line_valid_swap() {
assert_eq!(
parse_fstab_line("/dev/disk/by-uuid/102799bd-d9d2-4ef6-936f-6ba9b59f168e none swap"),
Some(FSTabEntry {
spec: "/dev/disk/by-uuid/102799bd-d9d2-4ef6-936f-6ba9b59f168e",
file: "none",
fs_type: "swap",
options: "",
dump: 0,
fsck_pass: 0,
})
);
}
#[test]
fn parse_fstab_line_invalid_too_many_fields() {
assert_eq!(
parse_fstab_line("/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc / ext4 defaults 0 1 # foo # bar"),
None,
);
}
#[test]
fn parse_fstab_comments_and_blank_lines() {
assert_eq!(
parse_fstab("
# This is a generated file. Do not edit!
#
# To make changes, edit the fileSystems and swapDevices NixOS options
# in your /etc/nixos/configuration.nix file.
# Filesystems.
# Swap devices.
".lines()),
FSTabFile {
entries: vec![],
},
);
}
#[test]
fn parse_fstab_morbo() {
assert_eq!(
parse_fstab("
# This is a generated file. Do not edit!
#
# To make changes, edit the fileSystems and swapDevices NixOS options
# in your /etc/nixos/configuration.nix file.
# Filesystems.
/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc / ext4 defaults 0 1
/dev/disk/by-uuid/2D03-B634 /boot vfat defaults 0 2
# Swap devices.
/dev/disk/by-uuid/102799bd-d9d2-4ef6-936f-6ba9b59f168e none swap
".lines()),
FSTabFile {
entries: vec![
FSTabEntry {
spec: "/dev/disk/by-uuid/3aa72460-7d05-4bd4-861f-6ef8b82082dc",
file: "/",
fs_type: "ext4",
options: "defaults",
dump: 0,
fsck_pass: 1
},
FSTabEntry {
spec: "/dev/disk/by-uuid/2D03-B634",
file: "/boot",
fs_type: "vfat",
options: "defaults",
dump: 0,
fsck_pass: 2
},
FSTabEntry {
spec: "/dev/disk/by-uuid/102799bd-d9d2-4ef6-936f-6ba9b59f168e",
file: "none",
fs_type: "swap",
options: "",
dump: 0,
fsck_pass: 0
},
],
},
);
}
#[test]
fn parse_fstab_utillinux_fstab_comment() {
// This fstab example is from util-linux 2.32.1's
// tests/ts/libmount/files/fstab.comment
assert_eq!(
parse_fstab("
#
# this is a leading comment
#
# this comments belongs to the first fs
UUID=d3a8f783-df75-4dc8-9163-975a891052c0 / ext3 noatime,defaults 1 1
UUID=fef7ccb3-821c-4de8-88dc-71472be5946f /boot ext3 noatime,defaults 1 2
# 3rd fs comment + newline padding
UUID=1f2aa318-9c34-462e-8d29-260819ffd657 swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
# this is comment
/dev/mapper/foo /home/foo ext4 noatime,defaults 0 0
foo.com:/mnt/share /mnt/remote nfs noauto
//bar.com/gogogo /mnt/gogogo cifs user=SRGROUP/baby,noauto
/dev/foo /any/foo/ auto defaults 0 0
#this is a trailing comment
".lines()),
FSTabFile {
entries: vec![
FSTabEntry {
spec: "UUID=d3a8f783-df75-4dc8-9163-975a891052c0",
file: "/",
fs_type: "ext3",
options: "noatime,defaults",
dump: 1,
fsck_pass: 1
},
FSTabEntry {
spec: "UUID=fef7ccb3-821c-4de8-88dc-71472be5946f",
file: "/boot",
fs_type: "ext3",
options: "noatime,defaults",
dump: 1,
fsck_pass: 2
},
FSTabEntry {
spec: "UUID=1f2aa318-9c34-462e-8d29-260819ffd657",
file: "swap",
fs_type: "swap",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "tmpfs",
file: "/dev/shm",
fs_type: "tmpfs",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "devpts",
file: "/dev/pts",
fs_type: "devpts",
options: "gid=5,mode=620",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "sysfs",
file: "/sys",
fs_type: "sysfs",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "proc",
file: "/proc",
fs_type: "proc",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "/dev/mapper/foo",
file: "/home/foo",
fs_type: "ext4",
options: "noatime,defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "foo.com:/mnt/share",
file: "/mnt/remote",
fs_type: "nfs",
options: "noauto",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "//bar.com/gogogo",
file: "/mnt/gogogo",
fs_type: "cifs",
options: "user=SRGROUP/baby,noauto",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "/dev/foo",
file: "/any/foo/",
fs_type: "auto",
options: "defaults",
dump: 0,
fsck_pass: 0
},
],
},
);
}
#[test]
fn parse_fstab_utillinux_fstab_broken() {
// This fstab example is from util-linux 2.32.1's
// tests/ts/libmount/files/fstab.broken
assert_eq!(
parse_fstab("
bug
UUID=d3a8f783-df75-4dc8-9163-975a891052c0 / ext3 noatime,defaults 1 1
UUID=fef7ccb3-821c-4de8-88dc-71472be5946f /boot ext3 noatime,defaults 1 2
UUID=1f2aa318-9c34-462e-8d29-260819ffd657 swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620
sysfs /sys sysfs defaults 0 0
this is broken line with unexpected number of fields
proc /proc proc defaults 0 0
# this is comment
/dev/mapper/foo /home/foo ext4 noatime,defaults 1
foo.com:/mnt/share /mnt/remote nfs noauto
//bar.com/gogogo /mnt/gogogo cifs user=SRGROUP/baby,noauto
".lines()),
FSTabFile {
entries: vec![
FSTabEntry {
spec: "UUID=d3a8f783-df75-4dc8-9163-975a891052c0",
file: "/",
fs_type: "ext3",
options: "noatime,defaults",
dump: 1,
fsck_pass: 1
},
FSTabEntry {
spec: "UUID=fef7ccb3-821c-4de8-88dc-71472be5946f",
file: "/boot",
fs_type: "ext3",
options: "noatime,defaults",
dump: 1,
fsck_pass: 2
},
FSTabEntry {
spec: "UUID=1f2aa318-9c34-462e-8d29-260819ffd657",
file: "swap",
fs_type: "swap",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "tmpfs",
file: "/dev/shm",
fs_type: "tmpfs",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "devpts",
file: "/dev/pts",
fs_type: "devpts",
options: "gid=5,mode=620",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "sysfs",
file: "/sys",
fs_type: "sysfs",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "proc",
file: "/proc",
fs_type: "proc",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "/dev/mapper/foo",
file: "/home/foo",
fs_type: "ext4",
options: "noatime,defaults",
dump: 1,
fsck_pass: 0
},
FSTabEntry {
spec: "foo.com:/mnt/share",
file: "/mnt/remote",
fs_type: "nfs",
options: "noauto",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "//bar.com/gogogo",
file: "/mnt/gogogo",
fs_type: "cifs",
options: "user=SRGROUP/baby,noauto",
dump: 0,
fsck_pass: 0
},
],
},
);
}
#[test]
fn parse_fstab_utillinux_fstab() {
// This fstab example is from util-linux 2.32.1's
// tests/ts/libmount/files/fstab
assert_eq!(
parse_fstab("
UUID=d3a8f783-df75-4dc8-9163-975a891052c0 / ext3 noatime,defaults 1 1
UUID=fef7ccb3-821c-4de8-88dc-71472be5946f /boot ext3 noatime,defaults 1 2
UUID=1f2aa318-9c34-462e-8d29-260819ffd657 swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
# this is comment
/dev/mapper/foo /home/foo ext4 noatime,defaults 0 0
foo.com:/mnt/share /mnt/remote nfs noauto
//bar.com/gogogo /mnt/gogogo cifs user=SRGROUP/baby,noauto
/dev/foo /any/foo/ auto defaults 0 0
".lines()),
FSTabFile {
entries: vec![
FSTabEntry {
spec: "UUID=d3a8f783-df75-4dc8-9163-975a891052c0",
file: "/",
fs_type: "ext3",
options: "noatime,defaults",
dump: 1,
fsck_pass: 1
},
FSTabEntry {
spec: "UUID=fef7ccb3-821c-4de8-88dc-71472be5946f",
file: "/boot",
fs_type: "ext3",
options: "noatime,defaults",
dump: 1,
fsck_pass: 2
},
FSTabEntry {
spec: "UUID=1f2aa318-9c34-462e-8d29-260819ffd657",
file: "swap",
fs_type: "swap",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "tmpfs",
file: "/dev/shm",
fs_type: "tmpfs",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "devpts",
file: "/dev/pts",
fs_type: "devpts",
options: "gid=5,mode=620",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "sysfs",
file: "/sys",
fs_type: "sysfs",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "proc",
file: "/proc",
fs_type: "proc",
options: "defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "/dev/mapper/foo",
file: "/home/foo",
fs_type: "ext4",
options: "noatime,defaults",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "foo.com:/mnt/share",
file: "/mnt/remote",
fs_type: "nfs",
options: "noauto",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "//bar.com/gogogo",
file: "/mnt/gogogo",
fs_type: "cifs",
options: "user=SRGROUP/baby,noauto",
dump: 0,
fsck_pass: 0
},
FSTabEntry {
spec: "/dev/foo",
file: "/any/foo/",
fs_type: "auto",
options: "defaults",
dump: 0,
fsck_pass: 0
},
],
},
);
}
}
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